READ OUT LOUD. Choose which marked text you prefer to practice with - macrons in verse form, or macrons in prose order, or accent marks in prose order, or focusing on the meter. You will find materials for all of these options below. :-)
VERSE MACRONS. Here is the verse text with macrons:
Milvus edax, nimiae quem nausea torserat escae,

Illa autem, Quid flēs? Cūr haec tua viscera crēdās,

PROSE MACRONS. Here is the same text with macrons written out in prose word order:
Milvus edax, quem nimiae escae nausea torserat, ait: "Hei mihi, māter, viscera ab ōre fluunt." Illa autem: "Quid flēs? Cūr haec viscera tua crēdās, quī, raptō vīvēns, sōla aliēna vomis?"
STRESS (ACCENT) MARKS. Here is the prose text with accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Milvus edax, quem nímiae escae naúsea tórserat, ait: "Hei mihi, mater, víscera ab ore fluunt." Illa autem: "Quid fles? Cur haec víscera tua credas, qui, rapto vivens, sola aliéna vomis?"
ELEGIAC COUPLET METER. Below I have used an interpunct dot · to indicate the metrical elements in each line, and a double line || to indicate the hemistichs of the pentameter line.
Milvus e·dax, nimi·ae quem· nausea· torserat· escae,

Ill~ au·tem, Quid· flēs? Cūr· haec tua· viscera· crēdās,

IMAGE. Here's an illustration for the fable (image source) from a 1621 edition of the emblems:

What follows is an unmarked version of the prose rendering to faciliate word searches: Milvus edax, quem nimiae escae nausea torserat, ait: "Hei mihi, mater, viscera ab ore fluunt." Illa autem: "Quid fles? Cur haec viscera tua credas, qui, rapto vivens, sola aliena vomis?"